The UK's most complete GLP-1 guide
Every Question Answered. Every Side Effect Explained.
- How GLP-1 medications work
- Mounjaro vs Wegovy compared
- Injection instructions
- Side effects & solutions
- What to eat on treatment
- FAQs answered
Free tracker included with every download this week
Is a 23 BMI good?
Yes, a BMI of 23 is considered good and falls within the healthy weight range according to NHS guidelines. A BMI between 18.5 and 24.9 is classified as healthy weight for UK adults, so at 23 you are comfortably within this optimal range. This suggests your weight is at a level associated with lower health risks compared to overweight or obese categories. However, BMI is just one measure of health — factors like fitness, muscle mass, and waist circumference also matter. Use our free BMI calculator above to check your personal BMI and understand what your result means for you.
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Calculate Your BMI Instantly
Enter your height and weight below. Supports both imperial (stone & lbs) and metric (kg). Results include NHS category, healthy weight range, and ethnicity adjustments.
What Is BMI and Why Does It Matter?
Body Mass Index (BMI) is the most widely used screening tool for assessing whether your weight falls within a healthy range. Used by the NHS, GPs, and weight management services across the UK, BMI provides a quick snapshot of your weight relative to your height. The formula is simple: your weight in kilograms divided by your height in metres squared (kg/m²).
While BMI isn't a perfect measure — it doesn't account for muscle mass, bone density, or fat distribution — it remains the standard first step in identifying potential weight-related health risks including type 2 diabetes, cardiovascular disease, high blood pressure, and certain cancers.
The NHS also recommends adjusted thresholds for people of South Asian, Chinese, or Black African heritage — a BMI of 23 or above is classified as overweight, and 27.5 as obese. Our calculator includes this adjustment as a one-click toggle.
Where does a 23 BMI sit in the NHS categories?
According to NHS BMI categories, a BMI of 23 places you firmly in the healthy weight range of 18.5 to 24.9. This is the ideal BMI range where weight-related health risks are lowest. To put this in context, the full BMI range UK system works as follows:
- Below 18.5 = Underweight
- 18.5–24.9 = Healthy weight (your range)
- 25.0–29.9 = Overweight
- 30.0 and above = Obese
At a BMI of 23, you are roughly in the middle of the healthy band, offering good protection against weight-related conditions like type 2 diabetes, heart disease, and high blood pressure. If you're unsure of your own BMI, use the BMI calculator on this page to find out instantly — just enter your height and weight in either metric or imperial measurements.
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How It Works
Three simple steps to understand your weight and take action.
Enter your height and weight in our free calculator. Get your BMI, NHS category, healthy weight range, and ethnicity-adjusted thresholds instantly.
If your BMI suggests you're overweight or obese, explore our GLP-1 calculators to project potential weight loss on Mounjaro or Wegovy.
Use our progress tracker to log your weight weekly, visualise your journey with charts, and stay motivated — all stored privately in your browser.
Free Weight Loss Tools & Guides
Everything you need to understand your weight, explore medication options, and track your progress — completely free.
What are the limitations of BMI?
While a BMI of 23 is a positive indicator, BMI limitations mean it should not be your only health measure. BMI does not distinguish between muscle and fat — an athlete with high muscle mass may have a "high" BMI but low body fat percentage. Age, sex, and ethnicity also affect how BMI relates to health risk. For adults of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends lower thresholds, with 23 still being healthy but closer to the upper end. Waist circumference is equally important: men should aim for under 94cm (37 inches), women under 80cm (31.5 inches). Your GP can provide personalised health advice beyond BMI alone.
- Dual GIP/GLP-1 receptor agonist
- Up to 22.5% body weight loss (SURMOUNT-1)
- Weekly injection, dose escalation over 20+ weeks
- Available via private prescription in the UK
- Doses: 2.5mg → 5mg → 7.5mg → 10mg → 12.5mg → 15mg
- GLP-1 receptor agonist
- Up to 15–17% body weight loss (STEP trials)
- Weekly injection, 5-step dose escalation
- NHS & private prescription available
- Doses: 0.25mg → 0.5mg → 1mg → 1.7mg → 2.4mg
Mounjaro vs Wegovy: Head-to-Head
A side-by-side comparison of the two most popular GLP-1 weight loss medications available in the UK.
| Feature | Mounjaro | Wegovy |
|---|---|---|
| Drug class | Dual GIP/GLP-1 agonist | GLP-1 agonist |
| Active ingredient | Tirzepatide | Semaglutide |
| Avg. weight loss | 15–22.5% | 12–17% |
| Key trial | SURMOUNT-1 (2022) | STEP 1 (2021) |
| Max dose | 15 mg weekly | 2.4 mg weekly |
| Escalation period | 20–32 weeks | 16–20 weeks |
| Administration | Weekly injection (pen) | Weekly injection (pen) |
| NHS availability | Private prescription only | NHS & private |
| Approx. private cost | £150–£250/month | £150–£300/month |
| Common side effects | Nausea, diarrhoea, constipation | Nausea, vomiting, diarrhoea |
Data sourced from SURMOUNT-1 and STEP 1 clinical trials. Costs are approximate and vary by provider. Always consult a prescriber.
Am I Eligible for Weight Loss Medication?
In the UK, eligibility for GLP-1 weight loss medications like Mounjaro and Wegovy is based on your BMI and overall health profile.
- BMI of 30 or above (obese)
- Age 18 or over
- No contraindicated conditions
- Committed to lifestyle changes
- BMI of 27 or above
- Plus type 2 diabetes
- Or high blood pressure
- Or obstructive sleep apnoea
Use our BMI calculator to check whether your BMI falls within the eligible range.
How We Built These Tools
Every calculator and guide on myweightcheck is built with accuracy and transparency in mind. Our BMI calculator uses the standard WHO formula with NHS-aligned category thresholds. Our GLP-1 projections are modelled on published clinical trial data from SURMOUNT and STEP studies.
All data stays on your device. We don't require sign-ups, and we don't store your health information on any server. Your progress tracker saves data locally in your browser using localStorage, so only you can see it.
We're based in the UK and our tools are designed specifically for UK users — supporting stone & lbs by default, referencing NHS guidelines, using NICE-approved medication data, and linking to GPhC-registered pharmacies.
Frequently Asked Questions
Common questions about BMI, weight loss medications, and our free UK tools.
Is a BMI of 23 the same for men and women?
Yes, the NHS BMI categories are the same for both men and women. A BMI of 23 is healthy weight for any adult. However, body composition differs — women typically have higher body fat percentages at the same BMI than men due to natural hormonal differences. Waist measurement is also important for both sexes.
What weight gives a BMI of 23?
Your weight at BMI 23 depends on your height. Using the BMI formula, at 5ft 8in (173cm) a BMI of 23 equals approximately 69kg (10st 11lbs). At 5ft 5in (165cm) it equals about 62kg (9st 10lbs). Use our weight converter and BMI calculator to find your exact healthy weight range for your height.
Can I have a BMI of 23 and still be unhealthy?
BMI is a screening tool, not a complete health picture. You could have a healthy BMI but poor fitness, high stress, or other health conditions. Conversely, some very muscular individuals may have a slightly higher BMI but excellent health. Regular physical activity, balanced diet, and regular GP check-ups matter alongside BMI.
What's the difference between a 23 BMI and a 25 BMI?
A BMI of 25 marks the start of the overweight category, whilst 23 is safely in the healthy range. This small 2-point difference can represent 5–7kg depending on your height. The jump from healthy (24.9) to overweight (25) matters for health risk, which is why the NHS threshold is precisely set at 25.0.
Is a BMI of 23 the same across all ethnic groups?
The BMI value itself is calculated the same way, but health risk at BMI 23 differs by ethnicity. For South Asian, Chinese, Black African, and Black Caribbean adults, the NHS recommends lower BMI thresholds due to higher diabetes and heart disease risk at the same BMI. At 23, South Asian adults would be near the upper limit of their healthy range, whilst other groups have more buffer.
Ready to take control of your weight loss journey?
Start with a free BMI check, explore your GLP-1 options, or begin tracking your progress today. No sign-up. No cost. Just results.